Two Crown Prosecution Service employees have admitted making more than £1 million worth of bogus claims for taxi fares.

Finance manager Lisa Burrows and officer worker Tahir Mahmood were warned to expect "inevitable" jail terms after pleading guilty to fraud by abuse of position at Birmingham Crown Court.

Burrows, 41, of Oldbury, West Midlands, and Mahmood, 50, from Hodge Hill, Birmingham, are believed to have used the proceeds of the five-year scam to pay off a mortgage and fund trips to Dubai.

The pair, who will be sentenced in July, showed no obvious sign of emotion as they admitted conning the CPS out of £1,021,475 by producing invoices for a fictitious cab firm purporting to cater for witnesses.

Prosecutor Brian Dean told the court that investigators were still attempting to trace the proceeds of the fraud.

Asking Judge Nicholas Webb for the case to be adjourned until July 4, the barrister said ongoing inquiries into international bank accounts were being made by the Serious Organised Crime Agency.

Mr Dean added: "There is not, at the moment, any explanation for where the money has gone.

"A financial analyst is considering all the information so that a sentencing judge can be given a very clear idea of precisely what has happened to the money."

It was possible, Mr Dean said, that Mahmood had used £120,000 to clear a mortgage, while Burrows was thought to have visited Dubai on many occasions.

"These things need to be run to ground so that the sentencing judge has a full and accurate picture of the precise nature of the spending and the whereabouts of the money," Mr Dean said.

Burrows, of Titford Road, and Mahmood, of Eastbourne Avenue, were charged last month after an investigation by police acting on a complaint from the CPS.

Mahmood, thought to be a former taxi driver, worked for the CPS as an administrative assistant.

An earlier hearing at Birmingham Magistrates' Court was informed that he opened bank accounts using a different surname to facilitate the fraud.

The hearing at the lower court also heard that inquiries into Burrows' finances found evidence of expensive purchases of designer clothes, jewellery and holidays.

At the time of the previous hearing on February 28, no more than £1,400 had been found in accounts connected to Mahmood, who claimed no funds were left from the extensive fraud.

The CPS colleagues, both of previous good character, were remanded in custody pending the preparation of pre-sentence reports.

Judge Webb told them: "You have both pleaded guilty to what is a serious offence and both of you recognise that the court will impose a custodial sentence when you come back to be sentenced."

Burrows and Mahmood were both dismissed from their posts by the CPS on the day they first appeared in court.

Commenting on their guilty pleas, Malcolm McHaffie, deputy head of special crime for the CPS, said: "This was a significant fraud of at least £1,000,000 and those responsible have now been brought to justice.